Device for securing the outer end of a hairspring to the framework of a timepiece



July 26, 1966 'r. MONNIN 3,262,261 DEVICE FOR SECURING THE OUTER END OF TO THE AIRSPRING FRAMEWORK OF A TI PI Filed NOV. 9, l9

INVENTOR. Tho Honnin BY I MM/aw (g) E- United States Patent 3,262,261 DEVICE FOR SECURING THE OUTER END OF HAIRSPRING TO THE FRAMEWORK OF A TIME- PIECE Tho Monnin, Neuchatel, Switzerland, assignor to Ebauches S.A., Neuchatel, Switzerland Filed Nov. 9, 1964, Ser. N 0. 409,7 43 Claims priority, applidation Switzerland, Nov. 27, 1963, 14,503/ 63 3 Claims. (Cl. 58'115) The present invention relates to a device for securing the outer end of a hairspring to the framework of a timepiece. The device is characterized in that it includes a hairspring-stud rigidly supported by the framework and providing a vice the jaws of which are adapted to be closed by means of a screw, the jaws being provided with bearing surfaces shaped to clamp the hairspring.

The accompanying drawing shows, by way of example, one embodiment of the invention.

FIGURE 1 is a diagrammatic top view of said embodiment.

FIGURE 2 is a cross-sectional view thereof, at an enlarged scale.

The balance-cock 1 of the timepiece has a lug 2 supporting the device to be described hereinafter for securing the outer end of the hairspring 3. A regulator, which may be of any known type and which does not form a part of the present invention, is diagrammatically illustrated as at 4.

The device for securing the outer end of the hairspring 3 includes a stud 5 provided with a foot 6 engaged in a bore of the cock lug 2, the foot 6 being locked by a setscrew 7. The stud 5 consists of a metal block having a slot 8 extending horizontally over a large depth, so that it forms a sort of vice the jaws 9 and 10 of which may be brought nearer or moved away from each other by means of a screw 11. In the embodiment illustrated, the screw 11 is th-readedly engaged in the jaw 10 and its head 12 is lodged in a recess of the jaw 9. The jaws 9 and 10 are provided with grooves 13 and 14, respectively, which are adjacent to the slot 8, the bottoms of said grooves constituting together a well defined bearing surface for the hairspring 3 (see FIGURE 2). v

In order to secure the outer end of the hairspring 3, it is suflicient to place it in the grooves 13 and 14 of the jaws 9 and 10 of the stud 5, as shown in FIGURE 2, and to close the vice by tightening the screw 11. The hairspring 3 is thus compressed in the direction of its width and is wedged between the jaws 9 and 10, its position being very well determined.

As shown in FIGURE 1, the hairspring-stud 5 is preferably oriented or directed so that the straight line interconnecting the axes of the screw 11 and of the foot 6 forms an angle with the straight line interconnecting the axis of the foot 6 and the center of the hairspring 3, so that the portion of the hairspring 3 that lies beyond the regulator 4 extends more outwardly than if it would be concentric with the other windings of the hairspring 3. The orientation of the stud 5 may be easily varied by loosening the screw 7 and turning the stud 5 about its foot 6. Such a change in the orientation of the stud 5 makes it possible to improve the rating of the timepiece.

In order to bring the timepiece into beat, it is sufiicient to loosen the screw 11 and to slightly displace the hairspring 3 forward or backward with respect to the stud 5, and then to tighten the screw 11.

In the embodiment illustrated, the stud-holder, i.e. the lug 2 of the balance-cock 1, is shown as stationary, but it is of course also possible to provide other constructions in which the said stud-holder is rotatably mounted about the axis of the balance-wheel.

While I have described and illustrated one embodiment of my invention, I do not wish to unnecessarily limit the scope thereof, but reserve the right to make such modifications and rearrangements of the several parts as may comewithin the purview of the accompanying claims.

I claim:

1. A device for securing the outer end of a hair spring to the framework of a timepiece comprising a hair spring stud, supporting means for the stud adapted to be engaged in the framework, means defining a slot in the stud forming a pair of vice jaws, a screw extending through one of said vice jaws and the threadedly engaged in the other of said vice jaws so that the jaws are closed upon tightening of the screw, and means defining opposed recesses at the ends of the jaws, the surfaces of said recesses providing bearing surfaces for the hair spring.

2. A device according to claim 1 in which the supporting means is a foot having a circular wall extending from the stud, the foot adapted to be pivota-bly received in a circular opening in the timepiece framework, so that the stud may be oriented as desired.

3. A device according to claim 1 in which the screw head is positioned at the top of said hair spring stud opposite to said supporting means so that when in position in a timepiece framework, the screw head is outwardly of the framework.

References Cited by the Examiner FOREIGN PATENTS 1,145,347 10/1957 France.

RICHARD B. WILKINSON, Primary Examiner. GERALD F. BAKER, Examiner. 

1. A DEVICE FOR SECURING THE OUTER END OF A HAIR SPRING TO THE FRAMEWORK OF A TIMEPIECE COMPRISING A HAIR SPRING STUD, SUPPORTING MEANS FOR THE STUD ADAPTED TO BE ENGAGED IN THE FRAMEWORK, MEANS DEFINING A SLOT IN THE STUD FORMING A PAIR OF VICE JAWS, A SCREW EXTENDING THROUGH ONE OF SAID VICE JAW AND THE THREADABLY ENGAGED IN THE OTHER OF SAID VICE JAWS SO THAT THE JAWS ARE CLOSED UPON TIGHTENING OF THE SCREW, AND MEANS DEFINING OPPOSED RECESSES AT THE ENDS OF THE JAWS, THE SURFACES OF SAID RECESSES PROVIDING BEARING SURFACES FOR THE HAIR SPRING. 